The invention relates generally to the field of pulmonary drug delivery. More specifically, the invention relates to dry powder dispersion devices and methods for dispersing dry powder medicaments for inhalation by a patient.
Pulmonary drug delivery is becoming a promising way to deliver drugs to a patient. Pulmonary drug delivery relies on inhalation of a drug dispersion or an aerosol by the patient so that the active drug within the dispersion can reach the distal (alveolar) regions of the lung. It has been found that certain drugs are readily absorbed through the alveolar regions directly into blood circulation. For example, pulmonary delivery is particularly promising for the delivery of proteins and polypeptides which are difficult to deliver by other routes of administration. Such pulmonary delivery is effective both for systemic delivery and for localized delivery to treat diseases of the lungs.
A variety of approaches have been proposed to achieve pulmonary drug delivery. Such approaches include the use of liquid nebulizers, metered dose inhalers (MDI's) and dry powder dispersion devices. Of these approaches, dry powder dispersion devices are of particular interest. Exemplary embodiments of such dry powder dispersion devices are described in U.S. Pat. No. 5,740,794 and Ser. No. 08/309,691, filed Sep. 21, 1994, the complete disclosures of which are herein incorporated by reference. These patents describe hand-held powder dispersion devices which extract powder from a receptacle and aerosolize the powder so that the aerosolized powder may be inhaled by a patient. Such dry powder dispersion devices have proven to be tremendously successful in adequately aerosolizing dry powders for subsequent inhalation.
Even so, it would be desirable to provide various enhancements to increase the marketability, ease of use, functionality, and other features of such dry powder dispersion devices. Hence, it is an object of the invention to provide improved dry powder dispersion devices and methods for their use.